October 28, 2008--A spectrometer image of seemingly barren rock has scientists imagining a much wetter Mars.

NASA's Mars Reconnaissance Orbiter discovered a new category of hydrated minerals (cream-colored) that suggest liquid water existed on the red planet's surface just two billion years agoa billion years longer than previously theorized.

The deposits of hydrated silica, a material similar to opal, evidence locations once covered by water that shaped Mars's surface topography and might have made life possible.